Electrochemical oxidation of rhodamine B by PbO2/Sb-SnO2/TiO2 nanotube arrays electrode

A PbO2/Sb-SnO2/TiO2 nanotube array composite electrode was successfully synthesized and its electrochemical oxidation properties were investigated. Field-emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) results showed that the PbO2 coating was composed of an alpha-PbO2 inner layer and a beta-PbO2 outer layer. Accelerated life measurement indicated that the composite electrode had a lifetime of 815 h. Rhodamine B (RhB) was employed as a model pollutant to analyze the electrocatalytic activity of the electrode. The effects of initial RhB concentration, current density, initial pH, temperature, and chloride ion concentration on the electrochemical oxidation were investigated in detail. Inductively coupled plasma atomic emission spectroscopy (ICP-AES) results suggested that the concentration of leached Pb2+ in the electrolyte during the electrocatalytic oxidation process can be neglected. Finally, the degradation mechanism during the electrocatalytic oxidation process was proposed based on the results of solid-phase micro -extraction-gas chromatography-mass spectrometry (SPME-GC-MS). The high electrocatalytic performance of the composite electrode makes it a promising anode for the treatment of organic pollutants in aqueous solution. (C) 2019, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.